package com.sang.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;

//保存用户上一次访问的时间
public class CookieDemo01 extends HttpServlet {

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //服务器告诉你你来的时间，把这个时间封装成为一个信件，你下次来的时候带上，我就知道你来了

        //解决中文乱码
        resp.setContentType("text/html");
        req.setCharacterEncoding("utf8");
        resp.setCharacterEncoding("utf8");

        PrintWriter out = resp.getWriter();
        //Cookie,服务器端从客户端获取；
        Cookie[] cookies = req.getCookies();//这里返回数组，说明Cookie可能存在多个

        //判断Cookie是否存在
        if (cookies != null){
            //如果存在怎么办
            out.write("你上一次访问时间是:");

            for (int i = 0; i < cookies.length; i++) {
                Cookie cookie = cookies[i];
                //获取Cookie的名字
                if (cookie.getName().equals("lastLoginTime")) {
                    long lastLoginTime = Long.parseLong(cookie.getValue());
                    Date date = new Date(lastLoginTime);
                    out.write(date.toLocaleString());
                }
            }
        } else {
            out.write("这是您第一此访问本站");
        }

        //服务器给客户端响应一个Cookie
        Cookie cookie = new Cookie("lastLoginTime", System.currentTimeMillis()+"");

        //设置Cookie有效期为一天
        cookie.setMaxAge(24*60*60);
        resp.addCookie(cookie);

    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}
